// Muduo - A reactor-based C++ network library for Linux
// Copyright (c) 2010, Shuo Chen.  All rights reserved.
// http://code.google.com/p/muduo/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//   * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//   * Neither the name of Shuo Chen nor the names of other contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


#ifndef CLUSNET_BASE_MUTEX_H
#define CLUSNET_BASE_MUTEX_H

#include <clusnet/base/CurrentThread.h>

#include <mutex>
#include <cassert>
#include <pthread.h>
namespace clusnet
{
namespace base
{

class Mutex final
{
    public:
        Mutex(const Mutex&) = delete;
        Mutex& operator= (const Mutex&) = delete;
        Mutex()
            : holder_(0),
              mutex_()
        {}
        ~Mutex()
        {
            assert(holder_ == 0);
        }

    public:
        bool isLockedByThisThread() const
        {
            return holder_ == CurrentThread::tid();
        }

        void assertLocked()
        {
            assert(isLockedByThisThread());
        }

        void lock()
        {
            mutex_.lock();
            assignHolder();
        }

        void unlock()
        {
            unassignHolder();
            mutex_.unlock();
        }

        bool try_lock()
        {
            if (mutex_.try_lock())
            {
                assignHolder();
                return true;
            }
            return false;
        }

    private:
        void assignHolder()
        {
            holder_ = CurrentThread::tid();
        }
        void unassignHolder()
        {
            holder_ = 0;
        }

    private:
        pid_t holder_;
        std::mutex  mutex_;
};
}
}

#endif 
